CVE-2026-31667 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, system administrators using force-feedback gamepads with uinput, security teams assessing exposure in Linux kernel-based systems, and operators managing Linux kernel versions and updates in production environments should all be aware of this vulnerability and take necessary actions to verify and mitigate exposure.

Why it matters

A circular locking dependency warning can be triggered when using a force-feedback gamepad with uinput in the Linux kernel, requiring verification of Linux kernel versions and assessment of exposure.

• Verification of Linux kernel versions used in systems with force-feedback gamepads and uinput is required.
• Assessment of exposure and prioritization of verification is necessary for Linux kernel developers and maintainers.
• Remediation or verification priority follows from the supplied corpus, which requires verification from the supplied official sources.

Technical summary

A lockdep circular locking dependency warning can be triggered reproducibly when using a force-feedback gamepad with uinput in the Linux kernel. The cycle is caused by four lock acquisition paths. Fix this by introducing a new state_lock spinlock to protect udev->state and udev->dev access in uinput_request_send() instead of acquiring udev->mutex. This fix requires verification from the supplied official sources, and Linux kernel developers and maintainers should assess exposure and prioritize verification of Linux kernel versions used in systems with force-feedback gamepads and uinput.

Defensive priority

Linux kernel developers and maintainers should assess exposure and prioritize verification of Linux kernel versions used in systems with force-feedback gamepads and uinput. This vulnerability requires verification from the supplied official sources.

Recommended defensive actions

• Review Linux kernel versions used in systems with force-feedback gamepads and uinput.
• Verify Linux kernel versions against the provided commit hashes.
• Assess exposure and prioritize verification of Linux kernel versions.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.

Evidence notes

The CVE record and source item provide details on the vulnerability and its fix. However, the corpus does not establish versions, exploitation, impact, or remediation beyond the provided information, which requires verification from the supplied official sources.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.